Wednesday, September 27, 2006

Animal "Speech" Project Aims to Decode Critter Communication

The fictional children's book character Dr. Dolittle easily understood animal chatter. But for the rest of us, the meaning behind creatures' clucks, rumbles, and whistles remains a mystery.

Now, researchers from several universities and institutions are working on an effort called the Dr. Dolittle Project, which aims to crack the code of animal communication.

Their work could help people gain a better understanding of animal behavior and hopefully allow researchers to improve care for wild and captive animal populations.

"For centuries humans have tried to teach animals to communicate like humans," said Michael Darre, an animal science professor at the University of Connecticut (UConn) in Storrs.

"And now we're getting to the point where we're saying, Wait a second. Why don't we learn their language instead of making them learn ours?"

(Related feature: "Calls in the Wild" in National Geographic magazine.)

Elephant Talk

In the past three years researchers with the project have captured sounds from a variety of animals, including African elephants, rhinos, horses, chickens, and bottlenose dolphins.

Scientists also videotape the animals' corresponding behavior and feed the data into a modified human speech-recognition program.

The program can alert scientists to a range of details, including physiological indicators, such as stress or whether the animal is in heat.

Mike Johnson, an assistant professor of computer and electrical engineering at Marquette University in Milwaukee, Wisconsin, leads the project.

"We wanted to find ways to apply the high-tech side of what you can do in speech processing, which has been used in human speech processing for a decade or more, and apply those ideas to the field of bioacoustics," he said.African elephants at the theme park wear collars with digital microphones to capture sound. Each night the collars are removed and the recorded information is analyzed.

Anne Savage, the park's senior conservation biologist, says understanding how pachyderms use vocalizations to communicate will help people better manage them in the wild and in captivity.

"There is a lot of information—such as individual identification, emotion, and function—that is encoded in their rumbles that we are just beginning to understand," she said.

One study at the park focused on measuring emotion in elephant voices.

Since elephants have a clear hierarchy, Savage wanted to see if subordinates got nervous around higher-ranking members, much like some humans do.

"A lot of people, when they have to go deliver bad news to their boss, they'll get a little nervousness in their voice," she explained. "And you can actually measure the amount of shaking in their voice."

Savage found that the same thing happens in elephants: When lower-ranking animals approach dominant ones, their rumble contained a nervous jitter.

Another study involved herd communication.

Before Animal Kingdom opened in 1998, pairs of elephants were brought in from other institutions, where they had lived together for ten or more years.

After arriving at the park, a new dominance hierarchy was established.

Savage wondered if elephants that had previously lived together would still communicate, even if the new ranking system separated them.

She discovered that the strong social bonds the elephants had previously forged won out.

"One of the things that was very clear in all of this is that best friends talk to each other all the time and are more likely to answer a call of their close friend than others," she said.

Shouting Whales

For more than ten years, UConn animal bioacoustics researcher Peter Scheifele has collected sounds from a threatened group of beluga whales in Canada's St. Lawrence River estuary.

After joining the Dolittle project two years ago, he made a breakthrough discovery: Under noisy conditions, such as those created by passing motor boats, the whales vocalized louder so that pod members could hear them.

Scientists call this a Lombard response, and humans do it too.

"The Lombard response has typically been thought of as a reflex attributable to complex mammals having speech," he said.

"However, it is now thought of as being a reflexive response by animals that have a need for sounds with specific meaning to be heard."

Songbirds and some primates also "talk" louder when noise levels rise, he says.